A soldier in the northeast of the Democratic Republic of the Congo opened fire on family members and others who had buried his son before he could get home to attend the ceremony. He killed 13 people, including 10 children, authorities said Sunday.

The attack left the soldier’s wife, in-laws and two of their children dead on Saturday night, before pointing his gun at other civilians, reported Lt. Jules Ngongo, an army spokesman in Ituri province, where the killings took place. Specifically, the shooting occurred in the village of Nyakova, on the shores of Lake Albert. “The soldier opened fire on everyone around him,” Ngongo said.

The soldier came home from his post in another village in the province to meet family and community members who had gathered to mourn his son, who died of natural causes on Thursday, said Baraka Muguwa Oscar, the village chief. “This soldier did not like the fact that his son was buried without his approval and in his absence,” he added.

The soldier, who was not identified, is a member of the Armed Forces of the Democratic Republic of the Congo, or FARDC, which is working on his capture, since he fled after the attack. An investigation was opened into the incident. “No matter what the case, the moment or the circumstances, you cannot take a person’s life. This is an act of indiscipline that will be judged by the courts,” says Ngongo.

Fighting in eastern Congo has been brewing for decades, as more than 120 groups fight for power, land and valuable mineral resources, while others try to defend their communities. Earlier this week, the United Nations warned of an increase in violence in the north-east of the country.